The subject matter disclosed herein relates to systems and methods for reducing attenuation in current transducers. More specifically, the subject matter disclosed herein relates to reducing attenuation caused by magnetic shielding around a current sensor within a current transducer.
Current transducers may be used for a variety of purposes, such as measuring an actual current input and/or output for devices and/or systems. A current transducer generally includes a current sensor paired with circuitry to receive, and in some embodiments, transform the input and/or output measured by the sensor. In certain applications, the current transducer may measure small currents, which create small magnetic fields. In these applications, the current sensor maybe surrounded by magnetic materials that reduce interference by external magnetic fields that could obscure the small magnetic fields. The magnetic materials may be highly permeable and continuous around the sensor to provide the most effective magnetic shield.
Since magnetic materials tend to have a high conductance, the magnetic materials may also create an electrically conductive shell around the current sensor. However, this electrically conductive shell can interfere with and attenuate the small magnetic fields generated by the small currents, which the current sensor is intended to measure. In some existing current transducers, the potting material used to stabilize the internal components of the device may flow in between the pieces of magnetic material, electrically isolating them. Because the potting material may generally interrupt the electrically conductive shell, the current sensor may operate correctly, or at least well enough. In other current transducers, because the magnetic materials are composed of discrete parts, they might not form an electrically conductive shell while still forming the magnetic shield. For other current transducers experiencing attenuation, systems may require calibration to operate properly. In sum, there exists a need for improved current transducers that operate with reduced attenuation and overcome the above-noted problems present in the prior art.